1. Field of the Invention
The present invention relates to a photoelectrochemical cell for decomposing water by irradiation with light.
2. Description of Related Art
There are conventionally known techniques for decomposing water into hydrogen and oxygen by irradiating an optical semiconductor with light.
For example, JP 51(1976)-123779 A discloses a technique for producing hydrogen or oxygen on the surfaces of an optical semiconductor electrode and a counter electrode facing each other in an electrolyte by irradiating the surface of the optical semiconductor electrode with light.
JP 04(1992)-231301 A discloses a water photolysis apparatus including a reaction tube in which an optical semiconductor layer is formed on the outer surface of a cylindrical conductor and a counter electrode is formed on the inner surface thereof. This apparatus is configured to separate the produced hydrogen and oxygen from each other by using the inner space and the outer space of the reaction tube. In this apparatus, since the optical semiconductor layer and the counter electrode are formed on the same conductor, there is no need to connect the optical semiconductor layer and the counter electrode electrically by a conducting wire or the like. Therefore, the ohmic loss, etc. can be reduced.